Continuation Passing Style

function ajax(url, callback){
 jQuery.ajax({url: url, success: callback});
}

function combine(scripts, callback){
 async.map(scripts, ajax, function(contents){
 callback(contents.join(""));
 });
}

function combine(scripts, callback){
 var data [];
 for(var i =0; l = scripts.length; i< l; ++i){
 (function (i){
 jQuery.ajax({

 url: scripts[i],
 success : function(response){
 data[i] = response;
 if(data.length === scripts.length){
 callback(data.join(""));
 }
 }
 });
 }(i));
 }
}